Measuring instrument.



M. G. RYPINSKI. MEASURING INSTRUMENT. APPLICATION FILED NOV. 18, 1907.

' Patented Feb. 28, 1911.

. 1 Q I I 37 6 1: 27

. IN ENTQR WITNESSES: v

' I AT'TORNEY ATE, UFTQQ MENTS, T0 ESTINGHOUSE ELECTRIC & MANUFACTURINGGQMPANY, 0? 35.551

PITTSBURG, PENNSYLVANIA, A CORPGRATION OF PENNSYLVANIA.

MEASURING INSTRUMENT.

Specification of Letters Patent.

Patented net; as, ism,

Application-filed November 18, 1907. Serial No. 402,727.

To all whom it may c'oncern:-'

Be it known that I, MAURIoE C. RYPINsKI, a citizen of the United States,and a resident of Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in MeasuringInstrnl'nents, of which the following is a specification.

My invention relates to electrical measuring instruments, and it has forits object to provide an instrument the parts of which have suchstructure and arrangement that the insulation of the movable coilthereof may not be subjected to high-voltage strains and the manufactureof the instrument may be greatly facilitated and cheapened.

Figure 1, of the accompanying drawings, is a vtransverse sectional Viewof an-instru ment constructed in accordance with my invention, and F 2is a rearv view of the instrument ofFig. 1, the casingheing removed.

The operating parts of the instrument are inclosed within a casin 1composed of suitable insulating .materia and provided with a glass front2, and the said part-s are supported by means of-"an annularmetallicplate. 3 that rests/against a shoulder on the interior andnear-the front of the casing. The instrumentis provided with supportingstuds 4 and 5,that fproject into the casing, the inner end of the stud 4being screwed into the plate-3 to assist in securing the said plate inposition. An insulating bushing 6 is screw-threaded upon the inner endof the stud 5 and also upon one end of a short stud bolt 7, the otherend of which is screwed into the plate 3.

- The operating parts of the instrument comprise two permanentbarmagnets 9 and 10 the main portions of which are substantiallysemi-circular and conform in shape to the interior of the casing, andthe ends of which are bent inwardly at nearly diametrically oppositepoints.

Independently secured,-by means of bolts 11, to one. pair of theadjacent inwardly turned ends of the respective magnets 9 and 10, aretwo pole pieces 12 and 13 having substantially semi-circularextremities, the said pole pieces being placed together to form anannular ring-shaped polar extremity common to both magnets. Similarlysecured to the-other pair of inwardly turned ends of the permanentmagnets are two con-- polar projections in such amanner that each magnetmay be inserted into and removed- 7 from the instrument independently oftheother.

Threaded upon the ring-shaped pole provided by the pole pieces 12 and 13is a coil 17 one side of which is movable in the air gap between thepole pieces 12 and 13 and the pole pieces 14 and 15, the said coil beingmounted upon pivot-pins 18 and 19 for which hearings are provided inscrews 20 and 21 that are threaded in brackets 22 and 23, respectively.The bracket 23 extends from the back of the casing to the plate 3 in thefront thereof, to which it is secured and electrically connected, andthe bracket I 22 spans the central opening in the plate 3 and is securedto said plate by means of suitably insulated bolts 24 and 25. The bolt25 is electrically connected at its rear end to one terminal of aseriesof resistance coils able coil is operated by the actuating forcesin the instrument, the inner ends of the springs being mechanicallysecured to the 'said coil and electrically connected respectively to itsterminals, and the outer ends thereof being secured respectively to arms30 and 31 carried by and electrically connected to the brackets 22 and23.

The movable element of the instrument carries a'pointer 32 that movesadjacent to a graduated scale 33. The movable coil 17 normallyoccupies'the position indicated in broken lines in Fig. 1, and is movedfrom right to left a distance proportional to the amount of currenttraversing the said coil, according to, well-understood principles.

Current traverses the instrument by way of the stud 4, the plate-3, thebracket 23, arm -31, spiral spring 29, coil 17, spiral spring 28, arm30, bracket 22, resistance coils 27 and terminal stud 5. j

Since all of the parts of the instrument except the bracket 22, theresistance coils 27 and the stud 5 are-electrically connected to theplate 3, the maximum difl'erence of potential between the coil 17 andadjacent parts is equal only to the drop of potential over the said0011, which is very small, and itwill,

therefore, (be understood that there is but slight strain upon theinsulation ofthe coil, Furthermore, since the instrument casing iscomposed of insulating material, the live parts of the instrument arethoroughlyprotected and all danger of accidental burning out of themovable coil is, therefore, obviated.

The parts of the instrument which require accurate adjustment ofposition, with respect to each other, are the magnet system and thebrackets 22 and 23 that are provided with the bearings'for the movablecoil, and the said parts are all independently secured to and are'alinedfrom the plate 3. In assembling the instrument, therefore, after theparts have been carefully finished, it is only necessary to secure them,one at a time, to the said plate without the use of jigs or othersimilar devices, and the parts Will be accurately disposed withreference to each other, the manufacture of the instrument being therebygreatly facilitated and cheap ened.

I claim as my invention: 1. An electrical measuring instrumentcomprising an insulating casing, supporting only one of them.

studs that project into the casing and serve as c1rcu1t term1nals forthe instrument, and a conductlng front plate which supports theoperating parts of the in strun1ent,'said plate belng secured totheisaid studs Within the casing but being electrically]connected: to

2. An electrical measuring" instrumeiit comprising an insulating casing,a magnet system, a coil, brackets provided with bearings for the movablecoil, a front plate within the casing to which the magnet system and thebrackets are secured, and supportconnected to only one of them,bracketscar ried by the said plate, (fne of which is insulated therefrombut-is connected to the stud that is also insulated therefrom, and amovable coil electrically connected between the brackets and supportedupon bearings therein. I

In testimony whereof, I have hereunto subscribed my name this 7th day ofNovember, 1907.

MAURICE C. RYPINSKI.

\Vitnesses WM. BRADSHAW, BIRNEY HINES.

